Entrained liquid elemental sulfur is detrimental to the performance and recovery efficiency of sulfur recovery process units utilized in the petroleum refining, natural gas processing, and petrochemical industries. The nature of the sulfur liquid formed in the sulfur condensing equipment of a sulfur recovery unit creates small-entrained liquid sulfur droplets, fog, or mist. Liquid mist eliminating pads are sometimes used in sulfur recovery unit condensers to remove the referenced entrained liquid sulfur but these devices are susceptible to high pressure drop, fouling, and plugging.
Gas-liquid parallel plate or parallel vane separators can be used as an alternate to mist eliminating pads to recover these entrained particles of liquid sulfur and sulfur bearing compounds. Parallel plate separators are less susceptible to plugging than mist eliminating pads and have a lower pressure drop during normal operating conditions.
Because elemental sulfur freezes at the relatively high temperature of approximately 239° F. when compared to the normal outlet operating temperature of the sulfur condensing equipment of approximately 300-350° F., upsets in the sulfur recover unit operation or unplanned shutdowns can cause any residual liquid sulfur that remains on the gas-liquid parallel plate separators to freeze causing a blockage in the gas flow path which requires significant maintenance to correct.